If I had some magic wand to change one thing with the Focus ST, it would be to relieve it of those “old age” pounds. Subtracting 700 pounds would have this model feeling just as nimble as it did in its younger days and of course shorten stopping distances and decrease lap times.

One of the most popular modifications to these cars has to be some form of diverter valve (blow-off valve) upgrade. Let’s face it: Turbochargers make cool sounds, and in stock form you just don’t hear it much at all.

Next up would be some type of ECU tuning. For approximately $500, one can gain an easy 15 to 20 horsepower and 60 or so lb.-ft. of torque. You can get even more with an E85 tune. The tune becomes more and more important and effective once you add more modifications. Other common mods are the ubiquitous intake and exhaust, which again the car really responds well to and, of course, add some satisfying flash and sound.

Looking for bang for the buck? A lower motor mount is a great modification. The stock ones are super soft and really allow lots of wheel hop and in general lots of noise when it bottoms out.

Our balance shaft delete is a great value at $35, too. It adds a good 3 to 7 horsepower and removes 19 pounds off the front of a FWD vehicle, 11 of which are rotating mass. So eliminating that allows the engine to get into the revs quicker–and the BOOST!

Some folks have had issues with the transmission. Synchronizers tend to go out. I do believe a lot of that has to do with driving style. I have heard that a firm (MFactory) is working on some upgraded synchros, though.
The standard dual mass flywheel and clutch setup is also problematic. There are upgraded units available from many aftermarket companies like Clutch Masters.

These engines aren’t indestructible, and people do blow them at times. Good, quality tuning and harmonious mod selection are essential. At this time, one limitation is the stock high-pressure fuel pump. There is no upgrade available presently, and it ultimately will limit the car’s maximum horsepower. Folks are adding “auxiliary fuel systems” by adding extra port-type injectors to remediate this issue. I’d bet a better high-pressure fuel pump is on the horizon, though.

We like to run an external oil catch can/separator and reroute the oil separator/PCV to them. A common issue with direct-injected cars is that fuel is no longer introduced on the inlet side of the motor. That means parts like the intake ports of the head and the backsides of the valves get gunked up with the oily vapors offered by the PCV system that normally would be washed away by a port injector’s fueling.

We have seen some oil starvation issues with the Duratec motor in general during autocross and track duty. Massive Speed System makes a great oil baffle system to keep oil around the oil pump’s pickup tube–even when experiencing extreme lateral loads. You’ll need to perform the aforementioned balance shaft delete while you’re in there. Another added bonus is that your oil capacity will now be up to 6 quarts, so oil stays cooler, is available to the pickup tube, and effectively lubricates longer.

Anyone also serious about handling will want to dial in alignment settings to their liking for superior traction and tire contact. Massive Speed System offers rear camber arms, toe control arms, and front and rear adjustable sway bar end links for just such activities.

If you’re shopping for one of these cars, I don’t see a huge difference in which year you pick. Be sure you like whatever seats are in the one you’re looking at. Some people love the Recaro seats that come in the higher-optioned cars, and some absolutely despise them. I’d personally search for one that hasn’t been too messed with. There are many examples with poorly executed modifications that might be costly to un-do.

Handling and comfort are quite good from the factory on these, so our first move would be a little more get up and go. They aren’t the lightest cars, so punching up the power a bit really makes a noticeable difference right off the bat. This can easily be done with a Cobb Accessport and a tune. Handling can simply be addressed with some sticker tires.

Our favorite first modifications are that Cobb Accessport as well as an intercooler. Remember, we’re creating a pretty substantial amount of heat when pushing the relatively small turbo even further. And while the Ford factory intercooler is a lightweight, mass produced piece, it doesn’t stand up to the additional charge temperatures.

We also do our own tuning work to make sure all the Focus STs we touch are making sufficient power responsibly. You can always upgrade to a bigger turbo to make more power, too (300 horsepowerplus reliably).

Once you have more power, a rear motor mount upgrade is needed to put that new power down. A limited-slip differential also helps if you are serious about putting the power down on track. We run the OS Giken Super lock LSD in our car, which makes a huge difference. The factory E-Diff can only do so much with the brakes, especially if they are stock. On track at any sort of speed, if you brake into a corner and then ask the same brakes to help you put the power down on exit with the E-diff, it will die a hot, quick death.

Two great low-buck modifications are the rear motor mount we mentioned before as well a short shift plate. For some reason, Ford decided the Focus ST shift throw should be the same as my uncle’s 1982 Ranger. A new shift knob should be added, too.

These cars can suffer from LSPI: Low Speed Pre Ignition. Basically, just don’t flat-foot it in fifth or sixth gear at low rpm, or things will go boom. That goes for pretty much any direct-injection engine these days. Other than this, the drivetrain is pretty solid.

Looking to start competing with your ST? Start with better tires. The stock Goodyears are great for daily duty, but fall on their face on track and in autocross. After you get the autocross bug, a rear anti-roll bar is the next step.

If you just bought a Focus ST, the first modifications will really depend on your intended use of the car. Many people modify the ST for many different uses, but the ST actually is very competitive in stock form for SCCA Solo G Street competition.

The Focus ST already has pretty decent tires (if it’s equipped with the standard Goodyear Eagle FIs and not the Pirelli all-seasons), they will handle moderate track and autocross use, but anything more on the hardcore side should upgrade to something more track worthy.

The OEM “torque vectoring system” in place of an actual mechanical LSD works decent on the street, but on track it really overcooks the brakes. I have seen Focus STs have their brakes glow without actually touching the brake pedal. A mechanical LSD swap is a huge help on this car, but most owners never get around to doing it, usually due to the pricing or hassle of having to pull out the transmission to install.

A set of good pads and a good DOT 4 fluid can go a long way on the ST. The OEM Focus ST frontmount intercooler is also a unit that should be replaced for sustained track use. We use a custom Mishimoto kit on our Time Attack car as well as many customer cars, and the difference is very drastic in charge air temps. In stock form the car can see over 200 degrees difference in air temps in less than one hard lap, which causes the stock ECU logic to pull away timing and boost to lower the power level to try to get the temps back down. With an upgraded intercooler kit, charge temps usually stay about 30–50 degrees higher than ambient temperature, even with severe track use.

On cars that see more sustained track usage, I also recommend an upgraded oil cooler as well.

Tuning is one of the best bang-for-the-buck modifications you can do to the ST. With just a Cobb Accessport and a custom tune from us, we can implement many upgraded features as well as nearly 30 horsepower and around 80 ft.-lbs. of torque. With a few bolt-ons such as an intercooler and high-flow downpipe, you can see close to 300 horsepower at the front wheels and over 400 ft.-lbs. of torque if desired.

Of course, being a tuner, a custom tune is my favorite modification. We can tune for more power, more torque, custom launch control, flat-foot shifting, custom spark cut, traction control–the list goes on and on. The options for tuning these cars are basically limitless.

CobraSpdRH wrote:
Even new 2017's seem to be getting heavily discounted.

They have $3500 in cash incentives right now which nudged me in the direction of new vs used. It sounds like they're really close to a redesigned 2018 model so it might pay to wait a bit and see if even better discounts come along.